The Cross-Flow Biofill of Velda is a flow filter, which has several advantages compared to different filter systems. Both its cleaning capacity and its biological action are larger than that of current filters. This property, combined with its simple installation, slight maintenance and ultimate water filtration makes this filter universally usable. The Cross-Flow Biofill ensures that pond water remains crystal clear and healthy. It can also be supplied as a complete set with a UV-C Unit and High-Stream pump.